Answer:
d. statistics about the salaries of people with post-secondary education
Step-by-step explanation:
In the text above, the author shows the importance of post-secondary education in the students' lives. According to the author, post-secondary education allows students to have their goals in focus, in addition to directing them to ways of seeking to achieve these goals. With that the students keep the focus on their personal, academic and economic growth and this focus allows them to have successful adult lives.
Based on this, we can say that the author would be able to support his position on the importance of post-secondary education if he showed statistics on the salaries of people with post-secondary education.